To the Editor.—The article by Dr Schoenenberger and colleagues1 reports that only 27% of antiepileptic drug level determinations had an appropriate indication. That is a misleading conclusion. Most test requests considered inappropriate were so classified because the blood sample was not drawn at the appropriate time. In my opinion, that is not inappropriate ordering, but rather represents an absence of systems at their institution to ensure that drug levels are drawn at the correct time.The article also failed to address an equally important question: How many patients in their medical complex were receiving drugs that should be monitored but were not monitored? Such information is essential to ensure that all appropriate actions are taken. Daily ordering of phenobarbital levels is clearly inappropriate, but failure to order a phenobarbital level periodically to ensure patient compliance or adequate drug absorption is also inappropriate.At the Columbia-Presbyterian Medical Center in